Platelet count decline: an early prognostic marker in critically ill patients with prolonged ICU stays

Serial platelet count as a dynamic prediction marker of hospital mortality among septic patients

Background

Platelets play a critical role in hemostasis and inflammatory diseases. Low platelet count and activity have been reported to be associated with unfavorable prognosis. This study aims to explore the relationship between dynamics in platelet count and in-hospital morality among septic patients and to provide real-time updates on mortality risk to achieve dynamic prediction.

Methods

We conducted a multi-cohort, retrospective, observational study that encompasses data on septic patients in the eICU Collaborative Research Database (eICU-CRD) and the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The joint latent class model (JLCM) was utilized to identify heterogenous platelet count trajectories over time among septic patients. We assessed the association between different trajectory patterns and 28-day in-hospital mortality using a piecewise Cox hazard model within each trajectory. We evaluated the performance of our dynamic prediction model through area under the receiver operating characteristic curve, concordance index (C-index), accuracy, sensitivity, and specificity calculated at predefined time points.

Results

Four subgroups of platelet count trajectories were identified that correspond to distinct in-hospital mortality risk. Including platelet count did not significantly enhance prediction accuracy at early stages (day 1 C-indexDynamic  vs C-indexWeibull: 0.713 vs 0.714). However, our model showed superior performance to the static survival model over time (day 14 C-indexDynamic  vs C-indexWeibull: 0.644 vs 0.617).

Conclusions

For septic patients in an intensive care unit, the rapid decline in platelet counts is a critical prognostic factor, and serial platelet measures are associated with prognosis.

Thrombocytopenia Independently Leads to Changes in Monocyte Immune Function

BACKGROUND

While platelets have well-studied hemostatic functions, platelets are immune cells that circulate at the interface between the vascular wall and white blood cells. The physiological implications of these constant transient interactions are poorly understood. Activated platelets induce and amplify immune responses, but platelets may also maintain immune homeostasis in healthy conditions, including maintaining vascular integrity and T helper cell differentiation, meaning that platelets are central to both immune responses and immune quiescence. Clinical data have shown an association between low platelet counts (thrombocytopenia) and immune dysfunction in patients with sepsis and extracorporeal membrane oxygenation, further implicating platelets as more holistic immune regulators, but studies of platelet immune functions in nondisease contexts have had limited study.

METHODS

We used in vivo models of thrombocytopenia and in vitro models of platelet and monocyte interactions, as well as RNA-seq and ATAC-seq (assay for transposase-accessible chromatin with sequencing), to mechanistically determine how resting platelet and monocyte interactions immune program monocytes.

RESULTS

Circulating platelets and monocytes interact in a CD47-dependent manner to regulate monocyte metabolism, histone methylation, and gene expression. Resting platelet-monocyte interactions limit TLR (toll-like receptor) signaling responses in healthy conditions in an innate immune training-like manner. In both human patients with sepsis and mouse sepsis models, thrombocytopenia exacerbated monocyte immune dysfunction, including increased cytokine production.

CONCLUSIONS

Thrombocytopenia immune programs monocytes in a manner that may lead to immune dysfunction in the context of sepsis. This is the first demonstration that sterile, endogenous cell interactions between resting platelets and monocytes regulate monocyte metabolism and pathogen responses, demonstrating platelets to be immune rheostats in both health and disease.

Analysis of hematological indicators via explainable artificial intelligence in the diagnosis of acute heart failure: a retrospective study

Introduction

Acute heart failure (AHF) is a serious medical problem that necessitates hospitalization and often results in death. Patients hospitalized in the emergency department (ED) should therefore receive an immediate diagnosis and treatment. Unfortunately, there is not yet a fast and accurate laboratory test for identifying AHF. The purpose of this research is to apply the principles of explainable artificial intelligence (XAI) to the analysis of hematological indicators for the diagnosis of AHF.

Methods

In this retrospective analysis, 425 patients with AHF and 430 healthy individuals served as assessments. Patients' demographic and hematological information was analyzed to diagnose AHF. Important risk variables for AHF diagnosis were identified using the Least Absolute Shrinkage and Selection Operator (LASSO) feature selection. To test the efficacy of the suggested prediction model, Extreme Gradient Boosting (XGBoost), a 10-fold cross-validation procedure was implemented. The area under the receiver operating characteristic curve (AUC), F1 score, Brier score, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were all computed to evaluate the model's efficacy. Permutation-based analysis and SHAP were used to assess the importance and influence of the model's incorporated risk factors.

Results

White blood cell (WBC), monocytes, neutrophils, neutrophil-lymphocyte ratio (NLR), red cell distribution width-standard deviation (RDW-SD), RDW-coefficient of variation (RDW-CV), and platelet distribution width (PDW) values were significantly higher than the healthy group (p < 0.05). On the other hand, erythrocyte, hemoglobin, basophil, lymphocyte, mean platelet volume (MPV), platelet, hematocrit, mean erythrocyte hemoglobin (MCH), and procalcitonin (PCT) values were found to be significantly lower in AHF patients compared to healthy controls (p < 0.05). When XGBoost was used in conjunction with LASSO to diagnose AHF, the resulting model had an AUC of 87.9%, an F1 score of 87.4%, a Brier score of 0.036, and an F1 score of 87.4%. PDW, age, RDW-SD, and PLT were identified as the most crucial risk factors in differentiating AHF.

Conclusion

The results of this study showed that XAI combined with ML could successfully diagnose AHF. SHAP descriptions show that advanced age, low platelet count, high RDW-SD, and PDW are the primary hematological parameters for the diagnosis of AHF.

Peripheral Veno-Arterial-Extracorporeal Membrane Oxygenation for Refractory Septic Shock in Children: A Multicenter Review

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is utilized as a rescue therapy in the management of pediatric patients with refractory septic shock. Multiple studies support the use of a central cannulation strategy in these patients. This study aimed to assess the survival of and identify mortality risk factors in pediatric patients supported with peripheral veno-arterial (VA) ECMO in the setting of septic shock.

METHODS

We retrospectively reviewed and compared clinical characteristics of 40 pediatric patients supported with peripheral VA ECMO for refractory septic shock, at two tertiary care children's hospitals from 2006 to 2020. Our hypothesis was that peripheral VA ECMO is effective in supporting cardiac function and improving tissue oxygenation in most pediatric patients with refractory septic shock.

RESULTS

The overall rate of survival to discharge was 52.5%, comparable to previously reported survival for pediatric sepsis on ECMO. With the exclusion of patients with an oncologic process, the survival rate rose to 62.5%. There was a statistically significant difference in mean pump flow rates within 2 hours of initiation of ECMO between survivors and non-survivors (98 mL/kg/min vs 76 mL/kg/min, P  =  .050). There was no significant difference between pre-ECMO vasoactive inotropic score (VIS) in survivors and non-survivors. A faster decrease in VIS in the first 24 hours was associated with lower mortality.

CONCLUSIONS

From this large case series, we conclude that peripheral VA ECMO is a safe and effective modality to support pediatric patients with refractory septic shock, provided there is establishment of high ECMO pump flows in the first few hours after cannulation and improvement in the VIS.

Reduced IgG2 with thrombocytopenia predicts mortality in patients with influenza pneumonia

BACKGROUND

Thrombocytopenia is a common disorder during influenza that is related to high mortality.

OBJECTIVES

A prospective study was performed to investigate the association of immunoglobulin subclass changes accompanying incident thrombocytopenia with clinical outcomes in patients with severe influenza.

METHODS

96 influenza patients were recruited and divided into two groups, patients with thrombocytopenia (n = 30) and patients without thrombocytopenia (n = 66). Plasma microarrays were used for quantitative analysis of immunoglobulins. The endpoint was 28-day mortality. Continuous platelet count, d-dimer, level of each Ig subclass and other variables were compared between the two groups. Kaplan-Meier curve was taken to analyze the 28-day survival rate of the two groups and Cox regression analysis was performed to identify variables independently associated with 28-day mortality.

RESULTS

Patients with thrombocytopenia had significantly high values of d-dimer at admission and when platelet lowest with high SOFA score. Their IgA2, IgG2, and IgG4 values were also lower than those without thrombocytopenia. Patients without thrombocytopenia had a higher 28-day survival rate than those in the thrombocytopenia group. In the multivariate Cox regression model, age (HR = 1.036, 95%CI = 1.011-1.062), IgG2 (HR = 0.990, 95%CI = 0.982-0.998), platelet minimum within 28 days (HR = 0.991, 95%CI = 0.982-0.999) and d-dimer when platelet lowest (HR = 1.091, 95%CI = 1.047-1.137) were independently related to 28-day mortality.

CONCLUSION

Decreased IgG2 may be associated with thrombocytopenia. A coexistence of thrombocytopenia, IgG2 reduction and d-dimer elevation may improve the accuracy of mortality prediction in patients with influenza pneumonia.

Prospective evaluation of bleeding risk among thrombocytopenic patients admitted in intensive care unit

PURPOSE

Bleeding risk evaluation of thrombocytopenic patients admitted in ICU has been poorly investigated.

METHODS

A prospective observational study conducted in an 18-bed medical ICU. Consecutive patients with thrombocytopenia (<150 Giga/L) and no bleeding at admission were included.

RESULTS

Over one year, 91 patients were included, mainly men (63%), with an age of 61 [46-68] years and a SOFA score of 6 [3-8]. Twenty-three patients (25%) had an hemorrhagic event during ICU stay, mainly digestive (n = 9; 39%) and urological (n = 6; 26%). The time between ICU admission and bleeding was 8 [2-19] days. Almost half of bleeding events required vasopressor infusion and a hemostatic procedure. At admission, two variables were significantly different between the Bleeding and No-Bleeding groups: plasma urea level was significantly higher in the Bleeding group (9 [5.1; 13] vs. 13 [8.9; 31] mmol/L; p < 0.001) and the presence of skin purpura was associated with a 3-fold higher risk for bleeding during ICU stay (HR: 3.4 [1.3-8.3]; p < 0.05). In contrast, admission platelet count was not significantly different between the 2 groups (90 [32; 128] vs 62 [36; 103] G/L; p = 0.26).

CONCLUSION

Plasma urea levels and the presence of skin purpura are helpful in identifying thrombocytopenic patients at high-risk of bleeding during ICU stay.

The investigation of thrombocytopenia after transcatheter occlusion of patent ductus arteriosus

OBJECTIVE

To investigate the risk factors for thrombocytopenia after transcatheter occlusion operation of patent ductus arteriosus (PDA).

METHOD

Retrospective analyses were conducted using clinical data from 106 patients with PDA who underwent transcatheter closure operations at Henan Provincial Chest Hospital, Zhengzhou University, from January 2018 to June 2022. The study compared the changes in platelet counts before and after the operation, and investigated the risk factors for thrombocytopenia following PDA closure in different groups and layers.

RESULTS

The platelet count of patients with PDA significantly decreased after undergoing transcatheter PDA occlusion. Logistic regression analysis revealed that factors such as PDA diameter, occluder diameter, pressure difference on the two sides of the occluder, and residual shunt were associated with an increased risk of thrombocytopenia following PDA occlusion. Specifically, the size of the occluder and the pressure difference between the two sides of the occluder were found to have a negative correlation with the postoperative platelet count. Further subgroup analysis demonstrated that the incidence of total thrombocytopenia was significantly higher in the large PDA group compared to the small-medium PDA groups.

CONCLUSION

Our findings suggest that occluder diameter, the pressure difference between the two sides of the occluder, and the residual shunt are major risk factors correlated with the incidence of postoperative thrombocytopenia. However, a multicenter and long-term prospective study is required to further evaluate the prognosis of PDA patients with thrombocytopenia after transcatheter occlusion.

Multiorgan failure in patients after out of hospital resuscitation: a retrospective single center study

BACKGROUND

Information on extracerebral system dysfunction is important for assessing the needs of critically ill patients after cardiac arrest.

AIMS

To describe the prevalence of organ dysfunction and patient severity after out of hospital cardiac arrest (OHCA) using scores commonly used in intensive care and the association between these and mortality.

METHODS

Retrospective analysis of observational data collected in real time in a tertiary medical center where care withdrawal is mostly illegal. Adult patients after nontraumatic OHCA with ROSC who survived for more than two hours were included. Primary outcome-prevalence of organ failure, based on common definitions for organ dysfunction, in the 1 days of hospitalization. Secondary outcomes-rates of survival to hospital discharge and survival with a good neurological outcome (CPC 1 or 2), and associations between organ dysfunction SOFA and APACHE-II scores and outcomes. Associations were assessed using fisher's exact test for categorical variables and Mann-Whitney and T test for continuous variables. Multivariable models were also constructed for all measurements showing associations in previous tests. For severity scores compatibility, we used receiver-operating curve (ROC).

RESULTS

Overall 369 patients (median age 75 years, 65% male) were included. Most arrests (64%) were witnessed, bystander CPR was provided in 15%. Median call to arrival time was 4 min. The presenting rhythm was asystole in 48% and VT/VF in 22%. Cardiovascular causes of arrest predominated (48%, n = 178). The median length of hospitalization was 5 days. Overall 28% of the patients (n = 98) survived to hospital discharge, mostly with a good neurological status (18.7%, n = 57). The rates of organ dysfunction were: hemodynamic instability 65% (n = 247), respiratory dysfunction 94% (n = 296), kidney dysfunction 70% (n = 259), hepatic dysfunction 14% (n = 50). The median SOFA score on day 1 was 9 and the median APACHE II score was 34. Modeling was limited by missing data. Neurological dysfunction (i.e. GCS and seizures) and kidney injury were consistently correlated with the outcomes in the multivariable models. Severity of critical illness assessed by above scoring systems correlated with mortality (all ROC curves had an AUC ranging between 0.728 and 0.849).

CONCLUSIONS

Multiorgan failure is common after ROSC (1-4). Therefore, the management of patients after ROSC may require advanced multidisciplinary care. Scores describing the severity of critical illness should be routinely reported in resuscitation research. Our unique setting where withdrawal of care is illegal, allows assessment of extremely ill patients and may assist in defining margins for futility.

Impact of thrombocytopenia on short-term outcomes in patients undergoing mobile extracorporeal membrane oxygenation support

INTRODUCTION

The prolonged use of extracorporeal membrane oxygenation (ECMO) support is associated with increased consumption of platelets and hemolysis. The prognostic impact of thrombocytopenia prior to and during ECMO support on patient's short-, mid- and long-term outcomes has been critically evaluated and discussed over the last years. However, only few data have been published on thrombocytopenia caused by mobile ECMO support. The aim of this study was to evaluate the impact of thrombocytopenia on short-term outcomes and predictors of in-hospital mortality in patients supported by mobile ECMO for transportation and subsequent weaning in a tertiary centre.

METHODS

This retrospective single-centre study analyzed a total of 117 patients requiring mobile veno-arterial (va) ECMO support and subsequent transportation from referral hospitals to our department from January 2015 until December 2021. A total of 15 patients had to be excluded from the analysis for missing data regarding baseline platelet count. Patients were divided into two groups: thrombocytopenia group (<130 × 109/L, n = 44) and non-thrombocytopenia group (≥130 × 109/L, n = 58). The primary outcome was in-hospital mortality. Secondary outcomes were successful ECMO-weaning, and the incidence of associated complications (bleeding, acute hepatic failure, acute renal failure, dialysis, and septic shock).

RESULTS

The dialysis rate before ECMO initiation was significantly higher (p = .041) in the thrombocytopenia group compared to the non-thrombocytopenia group. The rates of bleeding complications (p = .032) and limb ischemia (p = .003) were significantly higher in patients with low platelet count. Moreover, complication rates of acute hepatic failure (p < .001), acute renal failure (p < .001) and dialysis (p = .033) were significantly higher in the thrombocytopenia group. Also, in-hospital mortality was significantly higher (p = .002) in patients with low platelet count before initiation of ECMO support.

CONCLUSION

Based on the results of the present study, patients with thrombocytopenia prior to mobile vaECMO support may be at significantly higher risk for associated complications and short-term mortality.

Clinical significance of thrombocytopenia in patients with septic shock: An observational retrospective study

PURPOSE

Whether thrombocytopenia in critically ill patients accounts for a bystander of severity or drives specific complications is unclear. We addressed the effect of thrombocytopenia on septic shock, with emphasis on intensive care unit (ICU)-acquired bleeding, infections and thrombotic complications.

MATERIALS AND METHODS

A retrospective (2008-2019) single-center study of patients with septic shock. Thrombocytopenia was assessed over the first seven days and was defined as severe (nadir <50 G/L), mild (nadir 50-150 G/L) and relative (30% decrease with nadir >150 G/L). Outcomes were ICU mortality and ICU-acquired complications defined by severe bleeding, infections and thrombotic events during the ICU stay.

RESULTS

The study comprised 1024 patients. Severe, mild and relative thrombocytopenia occurred in 33%, 40% and 9% of patients. The in-ICU mortality rate was 27%, independently associated with severe thrombocytopenia. ICU-acquired infections, hemorrhagic and thrombotic complications occurred in 27.5%, 13.3% and 11.6% of patients, respectively. Patients with severe, mild or relative thrombocytopenia exhibited higher incidences of bleeding events (20.3%, 15.3% and 14.4% vs. 3.6% in non-thrombocytopenic, p < 0.001), infections (35.2%, 21.9% and 33.3% vs. 23.1% in non-thrombocytopenic, p < 0.001) and thrombotic events (14.6%, 10.8% and 17.8% vs. 7.8% in non-thrombocytopenic, p = 0.03). Only severe thrombocytopenia remained independently associated with increased risk of bleeding.

CONCLUSIONS

Severe thrombocytopenia was independently associated with ICU mortality and increased risk of bleeding, but not with infectious and thrombotic events.

Development and Validation Nomogram for Predicting the Survival of Patients with Thrombocytopenia in Intensive Care Units

Background

The number of patients with thrombocytopenia (TCP) is relatively high in intensive care units (ICUs). It is therefore necessary to evaluate the prognostic risk of such patients.

Aim

This study investigated the risk factors affecting the survival of patients with TCP in the ICU. Using the findings of this investigation, we developed and validated a risk prediction model.

Methods

We evaluated patients admitted to the ICU who presented with TCP. We used LASSO regression to identify important clinical indicators. Based on these indicators, we developed a prediction model complete with a nomogram for the development cohort set. We then evaluated the mode's accuracy using a receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) in a validation cohort.

Results

A total of 141 cases of ICU TCP were included in the sample, of which 47 involved death of the patient. Clinical results were as follows: N (HR 0.91, 95% CI 0.86-0.97, P=0.003); TBIL (HR 1.98, 95% CI 1.02-1.99, P=0.048); APACHE II (HR 1.94, 95% CI 1.39, 2.48, P=0.045); WPRN (HR 6.22, 95% CI 2.86-13.53, P<0.001); WTOST (HR 0.56, 95% CI 0.21-1.46, P<0.001); and DMV [HR1.87, 95% CI 1.12-2.33]. The prediction model yielded an area under the curve (AUC) of 0.918 (95% CI 0.863-0.974) in the development cohort and 0.926 (95% CI 0.849-0.994) in the validation cohort. Application of the nomogram in the validation cohort gave good discrimination (C-index 0.853, 95% CI 0.810-0.922) and good calibration. DCA indicated that the nomogram was clinically useful.

Conclusion

The individualized nomogram developed through our analysis demonstrated effective prognostic prediction for patients with TCP in ICUs. Use of this prediction metric may reduce TCP-related morbidity and mortality in ICUs.

Thrombocytopenia Independently Leads to Monocyte Immune Dysfunction

In addition to their well-studied hemostatic functions, platelets are immune cells. Platelets circulate at the interface between the vascular wall and leukocytes, and transient platelet-leukocyte complexes are found in both healthy and disease states, positioning platelets to provide physiologic cues of vascular health and injury. Roles for activated platelets in inducing and amplifying immune responses have received an increasing amount of research attention, but our past studies also showed that normal platelet counts are needed in healthy conditions to maintain immune homeostasis. We have now found that thrombocytopenia (a low platelet count) leads to monocyte dysfunction, independent of the cause of thrombocytopenia, in a manner that is dependent on direct platelet-monocyte CD47 interactions that regulate monocyte immunometabolism and gene expression. Compared to monocytes from mice with normal platelet counts, monocytes from thrombocytopenic mice had increased toll-like receptor (TLR) responses, including increased IL-6 production. Furthermore, ex vivo co-incubation of resting platelets with platelet naïve bone marrow monocytes, induced monocyte metabolic programming and durable changes in TLR agonist responses. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-Seq) on monocytes from thrombocytopenic mice showed persistently open chromatin at LPS response genes and resting platelet interactions with monocytes induced histone methylation in a CD47 dependent manner. Using mouse models of thrombocytopenia and sepsis, normal platelet numbers were needed to limit monocyte immune dysregulation and IL6 expression in monocytes from human patients with sepsis also inversely correlated with patient platelet counts. Our studies demonstrate that in healthy conditions, resting platelets maintain monocyte immune tolerance by regulating monocyte immunometabolic processes that lead to epigenetic changes in TLR-related genes. This is also the first demonstration of sterile cell interactions that regulate of innate immune-metabolism and monocyte pathogen responses.

EASIX score predicts inferior survival after allogeneic hematopoietic cell transplantation

The Endothelial Activation and Stress Index (EASIX) is a prognostic tool that uses common clinical laboratory values and has been shown to predict non-relapse mortality (NRM) and overall survival (OS) at the onset of acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). We hypothesized that EASIX calculated at different time points pre- and post- HCT may predict NRM and OS, and that EASIX calculated at onset of GVHD may predict response to steroids. We evaluated the EASIX score pre- and post-HCT in 152 patients with lymphoid malignancies undergoing unmodified reduced intensity conditioning (RIC) alloHCT with uniform GVHD prophylaxis. In multivariate analysis, EASIX calculated pre-HCT was significantly associated with higher NRM (HR = 1.64, p = 0.009) and lower OS (HR = 1.33, p = 0.046). Furthermore, EASIX calculated at day 30 and at day 100 was associated with increased NRM (HR = 1.65, p < 0.001; and HR = 1.65, p < 0.001) and decreased OS (HR = 1.27, p = 0.018; and HR = 1.49, p < 0.001), independent of HCT-CI, disease and conditioning regimen. Our study shows that high EASIX scores at various time points pre- and post-HCT are significantly associated with poorer overall outcomes. EASIX provides an independent and easily accessible tool to predict outcomes that can be complementary to other measures of risk stratification for patients undergoing HCT.

Association between minimal decrease in platelet counts and outcomes in septic patients: a retrospective observational study

OBJECTIVES

Although platelets have been linked to inflammatory development in sepsis, knowledge on their role as an indicator in sepsis treatment is scarce. Here, we investigated the association between time-dependent changes in platelet counts with mortality rates to reveal the role of platelets in sepsis therapy.

DESIGN

A retrospective cohort study.

SETTING

We screened the Medical Information Mart for Intensive Care (MIMIC-IV), a public database comprising data from critical care subjects at the Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts, USA.

PARTICIPANTS

A total of 7981 patients, who were admitted to the BIDMC between 2008 and 2019, were analysed based on Sepsis-3 criteria from MIMIC-IV.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary and secondary outcomes included 30-day mortality after admission and length of intensive care unit (ICU) stay and hospitalisation, respectively.

RESULTS

Patients with ≤10% reduction in proportion of platelet counts were associated with significantly lower 30-day mortality (14.1% vs 23.5%, p<0.001, Kaplan-Meier analysis, p<0.0001). Multivariable analysis revealed that decreased platelet-count percentage ≤10% on day 4 after ICU admission was associated with lower probability of 30-day non-survival (OR=0.73, 95% CI 0.64 to 0.82, p＜0.001). Patients in the ≤10% group had significantly shorter ICU stays than those in the >10% group (6.8 vs 7.5, p＜0.001). Restricted cubic spline curves revealed that mortality rates decreased with increase in proportion of platelet counts.

CONCLUSIONS

A ≤10% decrease in platelet-count percentage among sepsis patients after treatments is independently associated with decreased 30-day mortality, suggesting that changes in proportion of platelet counts after treatments could be an indicator for assessing the therapeutic effects of sepsis.

Incidence, outcomes and risk factors of barotrauma in veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome

BACKGROUND

Although acute respiratory distress syndrome (ARDS) patients are provided a lung rest strategy during extracorporeal membrane oxygenation (ECMO) treatment, the exact conditions of barotrauma is unclear. Therefore, we analyzed the epidemiology and risk factors for barotrauma in ARDS patients using ECMO in a single, large ECMO center in China.

METHODS

A retrospective analysis was performed on 127 patients with ARDS received veno-venous (VV) ECMO who met the Berlin definition. The epidemiology and risk factors for barotrauma during ECMO were analyzed.

RESULTS

Among 127 patients with ARDS treated with ECMO, barotrauma occurred in 24 (18.9%) during ECMO and 9 (7.1%) after ECMO decannulation, mainly in the late stage of ARDS (75%) and ≥8 days during ECMO (54.2%). Univariate and multivariate analyses showed that younger ARDS patients (OR = 0.953, 95%CI 0.923-0.983, p = 0.003) and those with pneumocystis jirovecii pneumonia (PJP) (OR = 3.15, 95%CI 1.070-9.271, p = 0.037), elevated body temperature after establishing ECMO (OR = 2.997, 95%CI 1.325-6.779, p = 0.008) and low platelet count after establishing ECMO (OR = 0.985, 95%CI 0.972-0.998, p = 0.02) had an increased risk of barotrauma during ECMO. There was no difference in ventilator parameters between patients with and without barotrauma. Barotrauma during ECMO was mainly related to the etiology of the disease and disease state.

CONCLUSION

There is a high incidence of barotrauma in ARDS patients during ECMO, even after ECMO decannulation. Young age, PJP, elevated body temperature and low platelet count after establishing ECMO are risk factors of barotrauma, and those patients should be closely monitored by imaging, especially in the late stage of ARDS.

Association between thrombocytopenia and the severity of Covid-19 infection among hospitalized Egyptian patients

Background

COVID-19, which is caused by the corona virus 2 that causes severe acute respiratory syndrome, causes a respiratory and systemic illness that in 10–15% of patients escalates to a severe form of pneumonia. Thrombocytopenia is frequent in patients with COVID-19. We aimed to evaluate the association between thrombocytopenia and the severity of COVID-19 infection in hospitalized patients.

Methods

A cross-sectional study was done on 800 Egyptian patients with confirmed covid-19 infection. They were divided into Group I (Mild): 200 symptomatic patients meeting the case definition for COVID-19 without radiological evidence of pneumonia or hypoxia. Group II (Moderate): 200 patients with clinical signs of non-severe pneumonia and radiological evidence of pneumonia. Group III (Severe): 200 patients with clinical signs of pneumonia plus: respiratory or lung dysfunction. Group IV: 200 critically ill patient in ICU: Acute respiratory distress syndrome (ARDS).

Results: there was a highly statistically significant difference between the studied groups regarding thrombocytopenia (p < 0.001). Thrombocytopenia was statistically higher in severe and critically ill patients. In addition, a statistically significant difference found in outcome among the studied groups (p < 0.05) {critically ill (40%), severe (17.5%)}. The most common cause of death was respiratory failure, which occurred in 28 severe patients (80%) and 65 critically ill patients (81.25%), followed by hemorrhage due to thrombocytopenia, which occurred in 7 severe patients (20%) and 15 critically ill patients, respectively (18.75%).

Conclusion

The Platelet count is a straightforward, inexpensive, as well as easily available laboratory parameter that is frequently linked to severe covid-19 infection and a significant death risk.

•

The latest novel corona virus disease pandemic shows a significant health concern.

•

Thrombocytopenia is frequent in COVID-19, statistically higher in severe and critically ill patients.

The common cause of death was respiratory failure, occurred in severe patients (80%) & critically ill patients (81.25%).

The 2nd one is hemorrhage due to thrombocytopenia, occurred in severe patients (20%) & critically ill patients (18.75%).

•

Plateletcount is a simple, inexpensive, and readily available laboratory parameter that is frequently linked to severe covid-19 infection and a significant death risk.

Association of platelet count with all-cause mortality from acute respiratory distress syndrome: A cohort study

Background

The purpose of this study was to investigate whether platelet count was associated with mortality in acute respiratory distress syndrome (ARDS) patients.

Methods

We analyzed patients with ARDS from Multi‐parameter Intelligent Monitoring in Intensive Care Database III (MIMIC‐III). Platelet count was measured at the time of intensive care unit (ICU) admission. The cox proportional hazard model and subgroup analysis were used to determine the relationship between the platelet count and mortality of ARDS, as well as the consistency of its association. The primary outcome of this study was 365‐day mortality from the date of ICU admission.

Result

This study enrolled a total of 395 critically ill patients with ARDS. After adjustment for age, gender and ethnicity, the multivariate cox regression model showed that the hazard ratios (HRs) (95% confidence intervals [CIs]) of platelet count <192 × 10⁹/L and >296 × 10⁹/L were 2.08 (1.43, 3.04) and 1.35 (0.91, 2.01), respectively, compared with the reference (192–296 ×10⁹/L). After adjusting for confounding factors, lower platelet count (<192 × 10⁹/L) was associated with increased mortality (adjusted HR, 1.71; 95% CI 1.06–2.76, p = 0.0284). However, there was no similar trend in the 30‐day (adjusted HR,1.02; 95% CI 0.54–1.94) or 90‐day (adjusted HR, 1.65; 95% CI 0.94–2.89) mortality. In the subgroup analysis, lower platelet count showed significant interactions with specific populations (p interaction = 0.0413), especially in patients with atrial fibrillation.

Conclusion

Taken together, our analysis showed that platelet count is an independent predictor of mortality in critically ill patients with ARDS.

Dose Escalation Trial of Desulfated Heparin (ODSH) in Septic Peritonitis

Objective

Septic peritonitis is associated with significant morbidity and mortality. As a potential therapeutic agent in the treatment of sepsis, 2-O, 3-O desulfated heparin (ODSH) reduces histones and platelet factor 4 (PF4) in mouse sepsis models. This pilot clinical trial evaluated the safety and effect of ODSH in client-owned dogs with septic peritonitis.

Interventions

In an IACUC-approved, open-label, prospective, dose-escalation clinical trial in 6 dogs with spontaneous septic peritonitis, ODSH administration was initiated following surgical explore to achieve source control. Acute patient physiology and laboratory evaluation (APPLE_fast and APPLE_full) scores on admission, source of septic peritonitis, requirement for vasopressors, the administration of blood products, and survival to discharge were recorded. Platelet count, cell free DNA (cfDNA) concentration, and platelet factor 4 (PF4) concentrations were measured at the time of each ODSH dosage. A dose of ODSH was administered every 8 hs for a total of 4 doses (maximum total dosage 75 mg/kg) based on a pre-determined escalation protocol. Patients were monitored in the ICU following administration for evidence of clinical hemorrhage.

Main Results

The mean APPLE_fast and APPLE_full scores on admission were 22 +/- 6 and 32 +/-10, respectively. Four dogs received 4 total dosages of ODSH and 2 dogs received 3 total dosages of ODSH intravenously. The mean total dosage of ODSH administered during the study period was 48.3 +/- 21.6 mg/kg. No dog required dose de-escalation or had any evidence of bleeding. Four dogs survived to discharge.

Conclusions

No adverse effects of ODSH administration were documented in dogs with septic peritonitis. A randomized controlled trial is necessary to evaluate ODSH as a novel therapeutic in the treatment of septic peritonitis.

A Network Meta-Analysis of Two Doses of Recombinant Human Thrombopoietin for Treating Sepsis-Related Thrombocytopenia

Previous studies suggest that sepsis remains a common critical illness with a global incidence of 31.5 million. The aim of this study was to evaluate the comparative therapeutic value of recombinant human thrombopoietin (rhTPO) in treating sepsis patients with thrombocytopenia. We conducted a comprehensive electronic search of PubMed, EMBASE, the Cochrane Library, and CNKI from its inception through December 31, 2021. Thirteen randomized controlled trials (RCTs) involving 963 patients were included. Network meta-analyses showed that rhTPO 300 U/kg/day and rhTPO 15000 U/day significantly increased the platelet (PLT) levels on the 7^th day and decreased the requirement of transfusion of red blood cells (RBCs), plasma, and PLT compared with IVIG and NAT. SUCRA showed that rhTPO 300 U/kg/day ranked first in terms of 28-day mortality (85.5%) and transfusion, including RBC (88.7%), plasma (89.6%), and PLT (95.2%), while rhTPO 15000 U/day ranked first for the length of the intensive care unit (ICU) stay (95.9%) and PLT level at day 7 (91.6%). rhTPO 300 U/kg/day may be the optimal dose to reduce 28-day mortality and transfusion requirements. However, rhTPO 15000 U/day may be the optimal dose for shortening the ICU stay and increasing the PLT level on the 7th day. However, additional studies to further validate our findings are needed.

Evolution of Platelet Activation Parameters During Septic Shock in Intensive Care Unit

During severe sepsis, platelet activation may induce disseminate microvascular thrombosis, which play a key role in critical organ failure. Crucially, most of the studies in this field have explored platelet-leukocyte interactions in animal models, or explored platelets under the spectrum of thrombocytopenia or disseminated intravascular coagulation and have not taken into account the complex interplay that might exist between platelets and leukocytes during human septic shock nor the kinetics of platelet activation. Here, we assessed platelet activation parameters at the admission of patients with sepsis to the intensive care unit (ICU) and 48 hours later. Twenty-two patients were enrolled in the study, thirteen (59.1%) of whom were thrombocytopenic. The control group was composed of twelve infection-free patients admitted during the study period. The activation parameters studied included platelet-leukocyte interactions, assessed by flow cytometry in whole blood, as well as membrane surface and soluble platelet activation markers measured by flow cytometry and dedicated ELISA kits. We also investigated platelet aggregation and secretion responses of patients with sepsis following stimulation, compared to controls. At admission, the level of circulating monocyte-platelet and neutrophil-platelet heterotypic aggregates was significantly higher in sepsis patients compared to controls and returned to a level comparable to controls or even below 48 hours later. Basal levels of CD62P and CD63 platelet membrane exposure at admission and 48 hours later were low and similar to controls. In contrast, plasma level of soluble GPVI and soluble CD40 ligand was significantly increased in septic patients, at the two times of analysis, reflecting previous platelet activation. Platelet aggregation and secretion responses induced by specific agonists were significantly decreased in septic conditions, particularly 48 hours after admission. Hence, we have observed for the first time that critically ill septic patients compared to controls have both an early and durable platelet activation while their circulating platelets are less responsive to different agonists.

The Relative Early Decrease in Platelet Count Is Associated With Mortality in Post-cardiotomy Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation

Background: The relationship between the magnitude of platelet count decrease and mortality in post-cardiotomy cardiogenic shock (PCS) patients undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) has not been well-reported. This study was designed to evaluate the association between the relative decrease in platelet count (RelΔplatelet) at day 1 from VA-ECMO initiation and in-hospital mortality in PCS patients.

Methods: Patients (n = 178) who received VA-ECMO for refractory PCS between January 2016 and December 2018 at the Beijing Anzhen Hospital were reviewed retrospectively. Multivariable logistic regression analyses were performed to assess the association between RelΔplatelet and in-hospital mortality.

Results: One hundred and sixteen patients (65%) were weaned from VA-ECMO, and 84 patients (47%) survived to hospital discharge. The median [interquartile range (IQR)] time on VA-ECMO support was 5 (3–6) days. The median (IQR) RelΔ platelet was 41% (26–59%). Patients with a RelΔ platelet ≥ 50% had an increased mortality compared to those with a RelΔ platelet < 50% (57 vs. 37%; p < 0.001). A large RelΔplatelet (≥50%) was independently associated with in-hospital mortality after controlling for potential confounders (OR 8.93; 95% CI 4.22–18.89; p < 0.001). The area under the receiver operating characteristic curve for RelΔ platelet was 0.78 (95% CI, 0.71–0.85), which was better than that of platelet count at day 1 (0.69; 95% CI, 0.61–0.77).

Conclusions: In patients receiving VA-ECMO for post-cardiotomy cardiogenic shock, a large relative decrease in platelet count in the first day after ECMO initiation is independently associated with an increased in-hospital mortality.

Mechanisms of immunothrombosis in COVID-19

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus-2. Over the past year, COVID-19 has posed a significant threat to global health. Although the infection is associated with mild symptoms in many patients, a significant proportion of patients develop a prothrombotic state due to a combination of alterations in coagulation and immune cell function. The purpose of this review is to discuss the pathophysiological characteristics of COVID-19 that contribute to the immunothrombosis.

RECENT FINDINGS

Endotheliopathy during COVID-19 results in increased multimeric von Willebrand factor release and the potential for increased platelet adhesion to the endothelium. In addition, decreased anticoagulant proteins on the surface of endothelial cells further alters the hemostatic balance. Soluble coagulation markers are also markedly dysregulated, including plasminogen activator inhibitor-1 and tissue factor, leading to COVID-19 induced coagulopathy. Platelet hyperreactivity results in increased platelet-neutrophil and -monocyte aggregates further exacerbating the coagulopathy observed during COVID-19. Finally, the COVID-19-induced cytokine storm primes neutrophils to release neutrophil extracellular traps, which trap platelets and prothrombotic proteins contributing to pulmonary thrombotic complications.

SUMMARY

Immunothrombosis significantly contributes to the pathophysiology of COVID-19. Understanding the mechanisms behind COVID-19-induced coagulopathy will lead to future therapies for patients.

Feature Explanations in Recurrent Neural Networks for Predicting Risk of Mortality in Intensive Care Patients

Critical care staff are presented with a large amount of data, which made it difficult to systematically evaluate. Early detection of patients whose condition is deteriorating could reduce mortality, improve treatment outcomes, and allow a better use of healthcare resources. In this study, we propose a data-driven framework for predicting the risk of mortality that combines high-accuracy recurrent neural networks with interpretable explanations. Our model processes time-series of vital signs and laboratory observations to predict the probability of a patient’s mortality in the intensive care unit (ICU). We investigated our approach on three public critical care databases: Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III), MIMIC-IV, and eICU. Our models achieved an area under the receiver operating characteristic curve (AUC) of 0.87–0.91. Our approach was not only able to provide the predicted mortality risk but also to recognize and explain the historical contributions of the associated factors to the prediction. The explanations provided by our model were consistent with the literature. Patients may benefit from early intervention if their clinical observations in the ICU are continuously monitored in real time.

Physiopathology and prospectives for therapeutic treatment of pulmonary fibrotic state in COVID-19 patients

The COVID-19 global pandemic has caused about 4,30 Mln deaths. Recently the first vaccines have been licensed, representing the most powerful weapon available to stop the pandemic. The COVID-19 viral infection in the most severe cases can cause severe lung lesions with the presence of fibrotic tissue. Even among cured individuals, the presence of pulmonary fibrotic tissue may be the major cause of long-term complications of COVID-19 requiring antifibrotic therapeutic treatment even in the post-COVID-19 infection phase to accelerate the healing process and fully recover lung function. This article reviews the fibrogenic mechanism of SARS-CoV-2-induced viral damage and the antifibrotic treatments indicated to treat sequelae post COVID-19 infection.

Bleeding risk of image-guided percutaneous catheter drainage of pyogenic liver abscess in patients with coagulopathy

OBJECTIVE

Percutaneous catheter drainage (PCD) is the mainstream treatment for pyogenic liver abscess (PLA). However, in some patients with severe coagulopathy, there may increase the risk of bleeding complications related to PCD. Therefore, this study was aimed to evaluate the incidence of bleeding complications of PCD in PLA patients complicated with coagulopathy.

METHODS

Between January 2011 and September 2019, patients diagnosed with PLA who had undergone PCD were selected retrospectively. Based on the preoperative coagulation parameters, the patients were divided into the coagulopathy group (PLT ≤ 50 × 10⁹/L or INR ≥ 1.5) and the normal coagulation group. The major and minor bleeding complications related to PCD were compared between the two groups. The ICU occupancy and mortality rates in the coagulopathy group were assessed and compared with patients of normal coagulation group.

RESULTS

A total of 583 PLA patients subjected to PCD were selected. 522 patients were finally included in this study: 64 cases (12.26%) in the coagulopathy group and 458 cases (87.74%) in the normal coagulation group. No major bleeding complications related to PCD was observed. Two patients (0.38%) of minor bleeding complications, one patient in each group, showed no statistically significant difference (0.2% vs.1.6%, P > 0.05). The ICU occupancy rate of coagulopathy group was significantly higher than normal coagulation group (6.2% vs. 0.7%, P < 0.05). No significant difference in mortality rate was noted between the two groups (4.7% vs.1.5%, P > 0.05).

CONCLUSION

The incidence of bleeding complications related to PCD in PLA patients is rare even if complicated with coagulopathy.

Thrombocytopenia and platelet count recovery in patients with sepsis-3: a retrospective observational study

Thrombocytopenia is common in critical illness. But there are no studies that focus on thrombocytopenia and platelet recovery in Sepsis-3 patients. We employed a large database to identify sepsis based on Sepsis-3 criteria. Patients were grouped by nadir platelet count during ICU, propensity score matching was used to eliminate covariates imbalance, multivariable cox proportional hazard model was used for evaluating mortality. A total of 9709 patients were enrolled based on Sepsis-3, 1794 (18%) patients developed thrombocytopenia, with 858 (8.8%) exhibiting thrombocytopenia at ICU admission (prevalent), 891 (9.2%) developed thrombocytopenia during ICU stay (incident). In the incident thrombocytopenia group, survivors exhibited higher nadir platelet count, higher rate in platelet count recovery and shorter time to platelet recovery compared to non-survivors. Platelet recovery was not observed until 1 days (IQR, 1-2) after weaning of mechanical ventilation and 1 days (IQR, 1-3) after discontinuation of vasopressor in survivors of incident thrombocytopenia. Furthermore, thrombocytopenia was associated with longer duration of ICU length of stay, longer duration of mechanical ventilation and vasopressor use compared to no thrombocytopenia. Moderate (20-50 × 10⁹/L) and severe (<20 × 10⁹/L) thrombocytopenia group showed increased 28 days mortality compared to no thrombocytopenia, while the mortality rate between mild (51-100 × 10⁹/L) and no thrombocytopenia group (≥100 × 10⁹/L) showed no significant difference. Taken together these data revealed that thrombocytopenia occurred in 18% Sepsis-3 patients; platelet recovery occurred more frequent and earlier in survivors; platelet recovery was not observed until clinical improvement. Thrombocytopenia in Sepsis-3 demonstrated increased disease severity, and patients with platelet count <50 × 10⁹/L showed increased 28 days mortality.

A descriptive and validation study of a predictive model of severity of SARS-COV-2 infection

Objectives

The strain the SARS-COV-2 pandemic is putting on hospitals requires that predictive values are identified for a rapid triage and management of patients at a higher risk of developing severe COVID-19. We developed and validated a prognostic model of COVID-19 severity.

Methods

A descriptive, comparative study of patients with positive vs. negative PCR-RT for SARS-COV-2 and of patients who developed moderate vs. severe COVID-19 was conducted. The model was built based on analytical and demographic data and comorbidities of patients seen in an Emergency Department with symptoms consistent with COVID-19. A logistic regression model was designed from data of the COVID-19-positive cohort.

Results

The sample was composed of 410 COVID-positive patients (303 with moderate disease and 107 with severe disease) and 81 COVID-negative patients. The predictive variables identified included lactate dehydrogenase, C-reactive protein, total proteins, urea, and platelets. Internal calibration showed an area under the ROC curve (AUC) of 0.88 (CI 95%: 0.85-0.92), with a rate of correct classifications of 85.2% for a cut-off value of 0.5. External validation (100 patients) yielded an AUC of 0.79 (95% CI: 0.71-0.89), with a rate of correct classifications of 73%.

Conclusions

The predictive model identifies patients at a higher risk of developing severe COVID-19 at Emergency Department, with a first blood test and common parameters used in a clinical laboratory. This model may be a valuable tool for clinical planning and decision-making.

Relative platelet reductions provide better pathophysiologic signatures of coagulopathies in sepsis

In sepsis-associated coagulopathies and disseminated intravascular coagulation, relative platelet reductions may reflect coagulopathy severity. However, limited evidence supports their clinical significance and most sepsis-associated coagulopathy criteria focus on the absolute platelet counts. To estimate the impact of relative platelet reductions and absolute platelet counts on sepsis outcomes. A multicenter retrospective observational study was performed using the eICU Collaborative Research Database, comprising 335 intensive care units (ICUs) in the United States. Patients with sepsis and an ICU stay > 2 days were included. Estimated effects of relative platelet reductions and absolute platelet counts on mortality and coagulopathy-related complications were evaluated. Overall, 26,176 patients were included. Multivariate mixed-effect logistic regression analysis revealed marked in-hospital mortality risk with larger platelet reductions between days one and two, independent from the resultant absolute platelet counts. The adjusted odds ratio (OR) [95% confidence intervals (CI)] for in-hospital mortality was 1.28[1.23–1.32], 1.86[1.75–1.97], 2.99[2.66–3.36], and 6.05[4.40–8.31] for 20–40%, 40–60%, 60–80%, and > 80% reductions, respectively, when compared with a < 20% decrease in platelets (P < 0.001 for each). In the multivariate logistic regression analysis, platelet reductions ≥ 11% and platelet counts ≤ 100,000/μL on day 2 were associated with high coagulopathy-related complications (OR [95%CI], 2.03 and 1.18; P < 0.001 and P < 0.001), while only platelet reduction was associated with thromboembolic complications (OR [95%CI], 1.43 [1.03–1.98], P < 0.001). The magnitude of platelet reductions represent mortality risk and provides a better signature of coagulopathies in sepsis; therefore, it is a plausible criterion for sepsis-associated coagulopathies.

Adult-onset Still's disease evolving with multiple organ failure and death: A case report and review of the literature

BACKGROUND

Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory disease, which is characterized by daily fever and arthritis, with an evanescent rash and neutrophilic leukocytosis. To date, there has been no definite laboratory or imaging test available for diagnosing AOSD; the diagnosis is one of exclusion, which can be very challenging. In particular, AOSD patients may experience different complications affecting their clinical picture, management, and prognosis. The treatment of AOSD remains largely empirical and involves therapeutic agents.

CASE SUMMARY

We report the case of a 36-year-old woman who presented with fever, red rash, arthralgia, and sore throat. Her serum ferritin level and white blood cell count were markedly elevated, and the first diagnosis 22 years prior was "juvenile rheumatoid arthritis of systemic type". The patient was treated with prednisone, sulfasalazine, methotrexate, and leflunomide. After remission of her symptoms, the patient stopped taking the medications, and the disease recurred. Ultimately, the patient was diagnosed with adult-onset Still's disease. Relapse occurred several times due to self-medication withdrawal, and an interleukin-6 antagonist (tocilizumab/Actemra) was administered to control the disease. Recently, she was hospitalized because an incision did not heal, and the patient suddenly developed high fever and diarrhea during hospitalization. The patient's disease progressed violently and quickly developed into macrophage activation syndrome, disseminated intravascular coagulation, shock, and multiple organ failure. The patient had sudden cardiac arrest, and she died despite emergency rescue efforts.

CONCLUSION

AOSD patients need regular follow-up in the long-term treatment process, and must press formulary standard medication, and do not voluntarily withdraw or reduce the dose. Otherwise it may cause disease back-and-forth or serious life-threatening complications. Meanwhile, strict management of trauma, infections, tumors, and other diseases may contribute to improved outcomes in patients with complications.

Angiotensin-(1-7) treatment blocks lipopolysaccharide-induced organ damage, platelet dysfunction, and IL-6 and nitric oxide production in rats

Sepsis can lead to shock, multiple organ failure, and even death. Platelets play an active role in the pathogenesis of sepsis-induced multiple organ failure. Angiotensin (Ang)-(1–7), a biologically active peptide, counteracts various effects of Ang II and attenuates inflammatory responses, reactive oxygen species production, and apoptosis. We evaluated the effects of Ang-(1–7) on organ injury and platelet dysfunction in rats with endotoxaemia. We treated male Wistar rats with saline or lipopolysaccharide (LPS, 10 mg, intravenously) then Ang-(1–7) (1 mg/kg, intravenous infusion for 3 h beginning 30 min after LPS administration). We analysed several haemodynamic, biochemical, and inflammatory parameters, as well as platelet counts and aggregation. Ang-(1–7) improved hypotension and organ dysfunction, and attenuated plasma interleukin-6, chemokines and nitric oxide production in rats after LPS administration. The LPS-induced reduction in platelet aggregation, but not the decreased platelet count, was restored after Ang-(1–7) treatment. The protein expression of iNOS and IκB, but not phosphorylated ERK1/2 and p38, was diminished in Ang-(1–7)-treated LPS rats. The histological changes in liver and lung were significantly attenuated in Ang-(1–7)-treated LPS rats. Our results suggest that Ang-(1–7) ameliorates endotoxaemic-induced organ injury and platelet dysfunction, likely through the inhibition of the inflammatory response and nitric oxide production.

Thrombocytopenia-Associated Multiple Organ Failure

Thrombocytopenia-associated multiple organ failure is a clinical phenotype encompassing a spectrum of syndromes associated with disseminated microvascular thromboses. Autopsies performed in patients that died with thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, or disseminated intravascular coagulation reveal specific findings that can differentiate these 3 entities. Significant advancements have been made in our understanding of the pathologic mechanisms of these syndromes. Von Willebrand factor and ADAMTS-13 play a central role in thrombotic thrombocytopenic purpura. Shiga toxins and the complement pathway drive the hemolytic uremic syndrome pathology. Tissue factor activity is vital in the development of disseminated intravascular coagulation.

Assessment of platelet biology in equine patients with systemic inflammatory response syndrome

In addition to maintaining hemostasis, platelets have an important role in modulating innate and adaptive immune responses. A low platelet count has been found to be a negative prognostic factor for survival in humans and horses with critical illnesses, such as sepsis or systemic inflammatory response syndrome (SIRS). Decreased platelet aggregation, caused by in vivo activation, has been found in human patients with severe sepsis. In our prospective controlled study, we assessed platelet biology in blood samples from 20 equine SIRS cases and 120 healthy control horses. Platelet variables such as platelet count, large platelet count, clumps, plateletcrit, mean platelet volume, and mean platelet component concentration were analyzed by laser flow cytometry (Advia 2120) from K₃EDTA blood and from citrate blood. Hirudin blood samples were analyzed by impedance aggregometry (Multiplate analyzer; Roche) for platelet aggregation, including spontaneous aggregation and aggregation by 4 different agonists: adenosine diphosphate (ADPtest), ADP + prostaglandin E1 (ADPtestHS), arachidonic acid (ASPItest), and collagen (COLtest). SIRS cases had significantly lower platelet counts in K₃EDTA blood (p < 0.0001) compared to control horses. There were no significant differences in aggregation values between SIRS cases and controls. Non-surviving SIRS horses did not have statistically significant lower platelet counts or lower aggregation values for COLtest, ADPtest, or ADPtestHS compared to surviving SIRS horses, although 5 non-survivors were thrombocytopenic.

Evaluation of the relationship of neutrophil-to lymphocyte ratio and platelet-to-lymphocyte ratio with in-hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease

INTRODUCTION

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has the highest mortality rate and medical costs. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte (PLR) ratio are inflammatory markers that have been recently linked to the AECOPD severity and patient outcome.

OBJECTIVE

Therefore, the present study aimed at evaluating the diagnostic value of NLR and PLR in the prognosis of the in-hospital mortality in AECOPD patients.

METHODS

The present retrospective study was performed on 829 AECOPD patients. Age, gender and laboratory results of CBC tests including lymphocyte count, neutrophil count, platelet count, hemoglobin count, white blood cell count (WBC), eosinophil cell count, NLR, PLR and CRP as well as the mortality data were collected from the patients' records and subsequently recorded.

RESULTS

The results of the present study revealed that NLR with the cut-off value of 6.90, sensitivity of 60.87%, and specificity of 73.29% had a significant diagnostic value in the prognosis of in-hospital mortality in AECOPD patients (P < 0.05). A similar significant finding regarding the diagnostic value in the prognosis of in-hospital mortality in AECOPD patients was obtained for CRP with the cut-off value of 30, sensitivity of 73.08%, and specificity of 60.26% (P < 0.05). However, the diagnostic value of PLR in the prognosis of in-hospital mortality in AECOPD patients was found to be insignificant (P = 0.18).

CONCLUSION

According to the results of the present study, NLR > 6.90 can be considered as a valuable and accurate marker in the prognosis of in-hospital mortality in AECOPD patients.

Thrombocytopenia in 737 adult intensive care unit patients: A real-world study of associated factors, drugs, platelet transfusion, and clinical outcome

Objective:

We aimed to identify and represent factors associated with thrombocytopenia in intensive care unit, especially the pathogens and drugs related to severe and extremely thrombocytopenia. Then, we aim to compare the mortality of platelet transfusion and non-transfusion in patients with different degrees of thrombocytopenia.

Methods:

We identified all thrombocytopenic patients in intensive care unit by using platelet-specific values and then extracted electronic health records from our Hospital Information System. Data were statistically analyzed with t test, chi-square test, and logistic regression.

Results:

We found that infections (32.7%) were the most frequent cause associated with thrombocytopenia, followed by sepsis shock (3.93%) and blood loss (2.99%). Meanwhile, antifungals (p = 0.002) and bacterial infection (p = 0.037) were associated with severe and extremely severe thrombocytopenia. Finally, we found that the mortality of platelet transfusion and non-transfusion in patients was statistically significant for patients with platelet counts between 30 and 49/nL (χ² = 9.719, p = 0.002).

Conclusion:

Infection and sepsis emerged as two primary factors associated with thrombocytopenia in intensive care unit. Meanwhile, antifungals and bacterial infection were associated with platelet counts less than 49/nL. Finally, platelet transfusion may be associated with reduced mortality in patients with platelet counts between 30 and 49/nL.

Platelet Dysfunction Diseases and Conditions: Clinical Implications and Considerations

INTRODUCTION

Platelet diseases and dysfunction are taught early in medical school to all future physicians. Understanding of the coagulation cascade and hemostatic mechanisms has allowed for targeted pharmacological therapies that have been significantly impactful in clinical practice. Platelets are an early participant in hemostasis physiologically and under pathophysiological states.

METHODS

A review of literature involving platelet disfunction.

RESULTS

Various presentations of platelet diseases and dysfunction challenge clinicians and require a firm understanding of normal platelet function, drugs that mediate or modulate platelet effectiveness, and nonpharmacologic etiologies of platelet diseases and dysfunction with corresponding best practice treatment approaches.

CONCLUSION

This review summarizes normal and abnormal states associated with platelets and treatment strategies.

Prognosis and rescue therapy for sepsis-related severe thrombocytopenia in critically ill patients

Sepsis is the most common critical disease with high mortality in intensive care unit. Platelet count (PC) frequently altered in sepsis patients and implicated in the pathogenesis of multi-organ failure. It is also worth mentioning that thrombocytopenia was closely associated with poor outcomes in sepsis patients. However, whether drug intervention aimed at correcting thrombocytopenia would improve the prognosis of sepsis patients and which kind of sepsis patients could benefit from this therapy is still unclear. This study aims to explore the effect of severe thrombocytopenia on the prognosis of sepsis and the impact of a platelet-elevating drug (recombinant human thrombopoietin, rhTPO) for these sepsis patients. In this study, we included 249 sepsis patients diagnosed by sepsis 3.0, and these patients were classified into the three groups based on PC: normal (PC ≥ 100 × 10⁹/L), mild-moderate thrombocytopenia (50 × 10⁹/L ≤ PC < 100 × 10⁹/L), and severe thrombocytopenia (PC < 50 × 10⁹/L). We found that patients with severe thrombocytopenia had more blood transfusion, shorter days free from organ support, and worse outcomes as compared with the normal group. However, there was no significant difference between normal and mild-moderate thrombocytopenia groups. Furthermore, a subgroup analysis showed that rescue therapy with rhTPO could rapidly lead to a recovery of the PC, prolong days free from organ support, increase survival days, and reduce the 28-day mortality in sepsis patients with severe thrombocytopenia. These results suggested that sepsis patients with severe thrombocytopenia, not mild-moderate thrombocytopenia, had a poorer prognosis. RhTPO, probably as effective rescue therapy, could quickly recover PC and improve the prognosis in these sepsis patients.

Role of platelet biomarkers in inflammatory response

Beyond hemostasis, thrombosis and wound healing, it is becoming increasingly clear that platelets play an integral role in inflammatory response and immune regulation. Platelets recognize pathogenic microorganisms and secrete various immunoregulatory cytokines and chemokines, thus facilitating a variety of immune effects and regulatory functions. In this review, we discuss recent advances in signaling of platelet activation-related biomarkers in inflammatory settings and application prospects to apply for disease diagnosis and treatment.

Types and outcomes of cytopenia in critically ill patients

Cytopenia is common complication in critically ill patients. Aim: Incidence and pattern of different types of cytopenia as well as its impact on mortality and length of stay in critically ill patients were evaluated. Methods: Critically ill patients with any kind of cytopenia for more than 2 days were evaluated. Results: Anemia was the most common type of cytopenia in the patients (99.14%), followed by lymphocytopenia (32.17%), thrombocytopenia (27.82%), and leukopenia (19.13%). Mortality rate was significantly higher in patients with anemia (p < 0.0001), thrombocytopenia (p < 0.0001), leukopenia (p < 0.0001), neutropenia (p = 0.004), lymphopenia (p = 0.002) and pancytopenia (p < 0.0001). Higher duration of anemia, lymphopenia and thrombocytopenia were associated with longer intensive care unit stay (p < 0.0001, p < 0.0001 and p < 0.001, respectively). Conclusion: Among all assessed variables, incidence of thrombocytopenia could independently predict the mortality.

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

Thrombocytopenia is a common complication of critical care patients. The rates of bleeding events and mortality are also significantly increased in critical care patients with thrombocytopenia. Therefore, the Critical Care Medicine Committee of Chinese People's Liberation Army (PLA) worked with Chinese Society of Laboratory Medicine, Chinese Medical Association to develop this consensus to provide guidance for clinical practice. The consensus includes five sections and 27 items: the definition of thrombocytopenia, etiology and pathophysiology, diagnosis and differential diagnosis, treatment and prevention.

Effects of Baseline Thrombocytopenia and Platelet Decrease Following Renal Replacement Therapy Initiation in Patients With Severe Acute Kidney Injury

OBJECTIVES

Thrombocytopenia is common in critically ill patients with severe acute kidney injury and may be worsened by the use of renal replacement therapy. In this study, we evaluate the effects of renal replacement therapy on subsequent platelet values, the prognostic significance of a decrease in platelets, and potential risk factors for platelet decreases.

DESIGN

Post hoc analysis of the Acute Renal Failure Trial Network Study.

SETTING

The Acute Renal Failure Trial Network study was a multicenter, prospective, randomized, parallel-group trial of two strategies for renal replacement therapy in critically ill patients with acute kidney injury conducted between November 2003 and July 2007 at 27 Veterans Affairs and university-affiliated medical centers.

SUBJECTS

The Acute Renal Failure Trial Network study evaluated 1,124 patients with severe acute kidney injury requiring renal replacement therapy.

INTERVENTIONS

Predictor variables were thrombocytopenia at initiation of renal replacement therapy and platelet decrease following renal replacement therapy initiation.

MEASUREMENTS AND MAIN RESULTS

Outcomes were mortality at 28 days, 60 days, and 1 year, renal recovery, renal replacement therapy free days, ICU-free days, and hospital-free days. Baseline thrombocytopenia in patients requiring renal replacement therapy was associated with increased mortality and was also associated with lower rates of renal recovery. A decrease in platelet values following renal replacement therapy initiation was associated with increased mortality. Continuous renal replacement therapy was not an independent predictor of worsening thrombocytopenia compared with those treated with intermittent hemodialysis.

CONCLUSIONS

Baseline thrombocytopenia and platelet decrease following renal replacement therapy initiation were associated with increased mortality, and baseline thrombocytopenia was associated with decreased rates of renal recovery. Continuous renal replacement therapy did not decrease platelets compared with hemodialysis.

Thrombocytopenia in the Intensive Care Unit

The evaluation and management of thrombocytopenia is a daily challenge for clinicians in the intensive care unit (ICU). Thrombocytopenia is incredibly common, present in upwards of 60% of ICU patients. Additionally, thrombocytopenia in the critically ill is rarely caused by a single etiology. Several causes of thrombocytopenia in the ICU including heparin-induced thrombocytopenia (HIT) and thrombotic thrombocytopenic purpura demand urgent recognition and intervention. This chapter provides a general overview of thrombocytopenia in the ICU and highlights important diagnostic and management considerations for some of the most common etiologies.

Cefepime challenge after piperacillin/tazobactam-induced thrombocytopenia

Drug-induced thrombocytopenia (DITP) has been described as a sudden and severe hematologic complication of piperacillin/tazobactam. The proposed mechanism by which piperacillin/tazobactam causes DITP involves the formation of a covalent bond to platelet membrane protein thereby inducing a humoral immune response. Given the immunogenic nature of this adverse event and the structural similarities across beta-lactam antibiotics, the potential for cross-reactivity between agents within the class should be considered. However, the structural moiety of piperacillin/tazobactam responsible for this immunogenic response has not been identified-the relationship between structure and activity for this phenomenon remains unknown. Data on the safety and cross-reactivity of other beta-lactam agents in this setting is lacking. We report the first case of piperacillin/tazobactam DITP successfully challenged by the use of cefepime for the treatment of aspiration pneumonia. Further studies are needed to determine the structural moiety of piperacillin/tazobactam responsible for this immunogenic response and evaluate the safety of other beta-lactam antibiotics in this clinical setting.

Post-transfusion platelet responses in critically ill cancer patients with hypoproliferative thrombocytopenia

BACKGROUND

Platelet transfusion is aimed at increasing platelet counts to prevent or treat bleeding. Critically ill cancer patients with hypoproliferative thrombocytopenia are high consumers of blood products. We herein described their post-transfusion platelet responses in the intensive care unit (ICU) and analyzed the determinants of poor post-transfusion increments.

STUDY DESIGN AND METHODS

This was a single-center 9-year (2009-2017) retrospective observational study. Patients with malignancies and presumed or proven hypoproliferative thrombocytopenia who had received at least one platelet transfusion in the ICU were included. Poor post-transfusion platelet increments were defined as body surface-adjusted corrected count increment (CCI) <7, or alternatively as weight-adjusted platelet transfusion recovery (PTR) <0.2. Patients were deemed refractory to platelet transfusions when two consecutive ABO-compatible transfusions resulted in poor platelet increments.

RESULTS

A total of 1470 platelet transfusions received by 326 patients were analyzed. Indications for platelet transfusions were distributed into prophylactic (44.5%), peri-procedural (18.1%) and therapeutic (37.4%). Regardless of indications, 54.6% and 55.4% of transfusion episodes were associated with a CCI <7 or a PTR <0.2. Factors independently associated with poor post-transfusion increments were lower body mass index, spleen enlargement, concurrent severity of clinical condition, fever ≥39°C, antibiotic therapy and increased storage duration of platelet concentrates. Eventually, 48 patients developed refractoriness to platelet transfusion, which was associated increased incidence of bleeding events.

CONCLUSION

Platelet transfusions are often associated with poor increments in critically ill cancer patients with hypoproliferative thrombocytopenia. The findings suggest amenable interventions to improve the platelet transfusion practices in this setting.

Prophylactic Platelet Transfusions for Critically Ill Patients With Thrombocytopenia: A Single-Institution Propensity-Matched Cohort Study

BACKGROUND

Thrombocytopenia is frequently encountered in critically ill patients, often resulting in prophylactic transfusion of platelets for the prevention of bleeding complications. However, the efficacy of this practice remains unclear. The objective of this study was to determine the relationship between prophylactic platelet transfusion and bleeding complications in critically ill patients.

METHODS

This is a retrospective cohort study of adults admitted to surgical, medical, or combined medical-surgical intensive care units (ICUs) at a single academic institution between January 1, 2009, and December 31, 2013. Inclusion criteria included age ≥18 years and a platelet count measured during ICU admission. Propensity-matched analyses were used to evaluate associations between prophylactic platelet transfusions and the outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of ICU and hospital-free days and changes in sequential organ failure assessment scores.

RESULTS

A total of 40,693 patients were included in the investigation with 3227 (7.9%) receiving a platelet transfusion and 1065 (33.0%) for which platelet transfusion was prophylactic in nature. In propensity-matched analyses, 994 patients with prophylactic platelet transfusion were matched to those without a transfusion. Patients receiving prophylactic platelets had significantly higher red blood cell transfusion rates (odds ratio 7.5 [5.9-9.5]; P < .001), fewer ICU-free days (mean [standard deviation] 20.8 [9.1] vs 22.7 [8.3] days; P = .004), fewer hospital-free days (13.0 [9.7] vs 15.8 [9.4] days; P < .001), and less improvement in sequential organ failure assessment scores (mean decrease of 0.2 [3.6] vs 1.8 [3.3]; P < .001) in the subsequent 24 hours. These findings appeared robust, persisting in multiple predefined sensitivity analyses.

CONCLUSIONS

Prophylactic administration of platelets in the critically ill was not associated with improved clinical outcomes, though residual confounding may exist. Further investigation of platelet transfusion strategies in this population is warranted.

Kinetics of mean platelet volume predicts mortality in patients with septic shock

Introduction

Thrombocytopenia is well recognized as a poor prognosis sign associated with increased mortality and prolonged Intensive Care Unit (ICU) stay, particularly in septic patients. Mean platelet volume (MPV) could represent a relevant predictive marker of mortality. Here we investigated whether MPV kinetics during the first 15 days after hospital admission has a potential prognostic value for clinical outcome in septic shock.

Methods

We performed a retrospectively analysis of a cohort of 301 septic patients admitted in ICU. Three-month mortality was the primary endpoint. The prognostic value of the covariates of interest was ascertained by multidimensional analysis. We proposed a classification and regression trees analysis to predict survival probability.

Results

MPV kinetics was significantly different between 90-day survivors and non-survivors when followed during 15 days (except on day 3). 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality (Hazard Ratio (HR) 3.796, 95% Confidence Interval (CI) [1.96–7.35], p = 0.0001) in multivariate analysis. Base excess on day 4 <1.9mmol/L was also a predictive factor of mortality (HR 2.972, 95%CI [1.38–6.40], p = 0.0054.

Conclusion

MPV increase during the first 15 days after ICU admission in non-survivors was observed during septic shock and 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality. This could be explained by the emergent response to acute platelet loss during septic shock, leading to megakaryocyte rupture to produce new but potentially immature platelets in the circulation. Therefore, continuous monitoring of MPV may be a useful parameter to stratify mortality risk in septic shock.